fix(copilot): render unclosed special tags as text on completed messages

The special-tag parser suppressed everything after an opening tag with no
close, even after streaming ended — so an assistant message that merely
MENTIONED `<workspace_resource>` in prose lost its entire remainder in the
UI. The stream itself completed fine; only the render truncated.

Suppression now applies only while streaming. A completed message can never
finish an unclosed tag, so the marker was literal text and the remainder is
rendered as-is.

Originally written alongside the docs/ VFS work and reverted at review time
to keep that PR to one concern; this restores it on its own.

Author: j15z

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/special-tags/special-tags.test.ts

@@ -149,6 +149,21 @@ describe('parseSpecialTags with <question>', () => {
     expect(segments).toEqual([{ type: 'text', content: 'Thinking about it. ' }])
   })
 
+  it('renders an unclosed tag as text once the message is complete', () => {
+    const content =
+      'The `<workspace_resource>` file chip only renders when its path points to a real file.'
+    const { segments, hasPendingTag } = parseSpecialTags(content, false)
+    expect(hasPendingTag).toBe(false)
+    expect(segments).toEqual([
+      { type: 'text', content: 'The `' },
+      {
+        type: 'text',
+        content:
+          '<workspace_resource>` file chip only renders when its path points to a real file.',
+      },
+    ])
+  })
+
   it('strips a trailing partial opening tag while streaming', () => {
     const { segments, hasPendingTag } = parseSpecialTags('Let me ask. <ques', true)
     expect(hasPendingTag).toBe(true)

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/special-tags/special-tags.tsx

@@ -526,8 +526,18 @@ export function parseSpecialTags(content: string, isStreaming: boolean): ParsedS
     const closeIdx = content.indexOf(closeTag, bodyStart)
 
     if (closeIdx === -1) {
-      hasPendingTag = true
-      cursor = content.length
+      if (isStreaming) {
+        hasPendingTag = true
+        cursor = content.length
+        break
+      }
+      // A completed message can never finish an unclosed tag — the marker was
+      // literal text mentioning the tag (e.g. "the `<workspace_resource>`
+      // chip"), not a real tag. Render the remainder instead of swallowing it.
+      const remaining = content.slice(nearestStart)
+      if (remaining.trim()) {
+        segments.push({ type: 'text', content: remaining })
+      }
       break
     }